Bounty Hunter Land Star Threshold

[SVEN1]

I picked up one of these older detectors in working condition. Would like to adjust the threshold down. I don't have and cannot find a schematic for the Land Star.
Does anyone know if there is an adjustment trimpot on the circuit board and or which one.

[SVEN1]

Found 4 trimpots on the PCB after opening the detector up.

[kt315]

maybe Melbeta will give a light? her file.

[Carl-NC]

R53 is the only possibility I can see for a threshold adjust. "ARM" feeds the micro, which then drives the speaker.

[SVEN1]

Thank you!!